Hello all. I was not diagnosed as having diabetes (the long story is here: http://www.diabetes.co.uk/forum/threads/hello-from-china-and-my-short-story.114713/) but from the test result, I believe I am at least prediabetic and bought a meter to monitor my BS levels so as to know what not to eat or eat much. The first day (yesterday) went fine with readings ranging in satisfactory levels (4.4-6.2 mmol/L) but it spiked to 7.5 mmol/L two hours after today's lunch (I ate similar foods and amounts as in the morning and last night). Then I started a 30-minute exercise and tested again, it read 3.1 mmol/L which is in the range of low blood sugar. I knew it couldn't be as I still felt energetic and strong. One hour later, I tested my sugar again and it read 4.7 mmol/L. Now I really suspect the accuracy of these readings. There are reports on my brand that some of its models could be 30% less than the real reading. I'm really puzzled and frustrated. I'm quite new about this and wonder how you, if you test your BS yourself using a meter, make sure the readings are accurate and reliable? There are also some articles saying all meters on the market are not accurate with 15%+ deviation and even hospital readings could be +/-4%. It is really scary if we rely on these meters, isn't it? Again, I am new and still learning. I hope you could share your experience and insights on this. Thanks.